Grease gun



Oct. 21, 1941. w. L. OSTENDORF GREAS E GUN Filed Jui 29, 1958 plunger-hammer I 4.

Patented Oct. 21, 1941 UNITED STATES ea-TE GREASE V William L. Ostendorf, Rayland, Ohio Application July 29, 1938, Serial No. 221.985

14' Claims. (01121-473) My invention relates to lubricant gunspar- .ticularly to guns known as booster guns, and more particularly to guns that operate on the principles of apneumatic hammer. The invention consists in certain refinements and improvements in structure, by virtue. of which more efilcient operation is realized;

' An exemplary embodiment of the invention is illustrated in the accompanying drawing, in which the gun is shown partly in axial sectio "and partly in side elevation.

The structure in which the invention is found includes a pistol-shaped body including a barrel B and a handle H. The bore of the barrelB provides a cylinder 20 to which lubricant is delivered (usually under superatmospheric pressure) from a supply, and in such cylinder a ram I9is reciprocable for forcing the lubricant under augmented pressure to the parts to. be lubricated. The muzzle of the gun includes a threaded socket S, through which the lubricant cylinder opens, and by means'of which the cylinder is connected to a fitting or a conduit leading to the ultimate point of lubricant delivery. 7 Inthis case, the supply of lubricant is held, above a pis- 1 ton P, in a container C; the container is carried "in' rigid though removable assembly with the gun; and the piston isbacked by a compressed 'helical spring D that maintains the store oflubricant under pressure. A port E provides communication' between the container and the ramcylinder 20. i

The ram is powerfully reciprocated in the cylinder '20 between the position shown, in ,which the port'E is'open to the fiow of lubricant from the container into the cylinder, and a position in which the port E is closed, and lubricant is ejectedfrom the cylinder, it being understood-that, in the initial movement of the ram from the position first mentioned, the body of the ram, advancing against the chargelof lubricant received from the supply, closes the port.. The means for reciprocating the ram are in- .cluded in a power'cylinder II arranged'in axial alignment with lubricant cylinder 20. The ram extends into the power cylinder, and is equipped with animpact-sustaining head 30. .The ram carries at an interval from such head a piston that engages the wall of the power cylinder in snug, sliding engagement. Beyond the 'head 30 of the ram, the power cylinder includes a The body of the gun includes a system of ports and passages communieating with a supply of compressed air, and, subject to the control of valves I, 6 and 2 I, presently to be described, these passages deliver com pressed air to the power'cylinder in such manner turned "to the start of its stroke, un'covering the port E to admit another charge of lubricant to the cylinder-.20.: These operations are automatic and are automatically repeated over and over again, subject, as will appear, to the .willof the user; i

To the end'that the structure may bereadily understood, 1 ,shall'describe in greater detail the operation of thegun through one'complete reciprocation of the; ram, and among the several novel and important features of invention which .will thus be presented; I-call particular. atten- Ltiontotwor x 'Fzrst I'o theiend-that"a maximum: charge of lubricant, even of the-heavier greases: shall be introduced to the cylinder 20, the reciprocating ram is arrested or delayed in port-uncovering position'." As-an' exampleof means for achieving this desideratum; I show .a device for retarding the movement of the raminto port-uncovering position. By utilization of such a device the port may be slowly opened, providing 'a'prolonged in terval of time in whichthelubricant may'fiow from container C'into cylinder '20. e

Second.The*ram I9 'operatesyonly against the lubricant in cylinder 20 during its power stroke. There is no other resistance to ram movement-savesuch resistance as is caused by mechanical friction; Underthe-drive of the reciprocating hammer element I4, the movement of the ram is'progressive from one end of its working stroke to the other; and there is no retrograde motion of 'the' ram, nor recoilfrom the blows delivered by' the hammer element.

The medium "for operating the gun is compressed air, but "other fluids under pressure may .be'used, and'theterm air is of general'significa'nce as used in the appended claims.

*The handle of the "gunincludes a passage F which is connectedtoa supply, of compressed air. A stop fvalve I, normally closed by ajspring, is

controlled bya trigger T., In order to efiect N T: Q F C operation of the gun, the trigger is pressed and held. In consequence the valve I opens and under trigger pressure is retained in open position; compressed air enters a passage 2 and flows to ports 3 and 4; and these ports, under the control of valve 6, are adapted to establish alternate lines of flow from the passage 2. One line of flow delivers air to the right-hand end of power cylinder H for reciprocating the hammer ele- 5 is closed and lubricant delivered under high pres-r sure from cylinder 20.

In such movement of the parts, the shoulder 28 on the hammer element is carried to the left of the ports [0, 12, before the blow is delivered ment, and -:the-rother:line delivers air"t0-the*-1eftto the'fram. "That is;'tcommunication between hand end.of:such..cylinder fortreturning the ram from the end of its lubricant-delivering stroke to recharging position. More specifically, the a valve 6 consists in a cylindrical plunger that is reciprocable in a cylinder 5 between alternate-"15-hammer positions of service. The plungeraincludes an axial passage 33 that permits displacement of air from one end of the cylinder to theother when the plunger is moved between its said alternate positions. The plunger carries a rigid finger '3 lthat extends' upwardfi'through -a slot 40,- into the power-cylinder g as will presently appear, the upper tip afi'the finger is aiternately"engaged by-1 head '30' and= pistoir flfioi the' reciprocating ram, and 'in consequence the finger isnntermit- I Shified fi-iSt- -in (unti -direction and them in thel other, cari'ying -the plunger valve 5 between its alternate positions' oi -service inI cylinder 5 the lower end of the fin'gefi 3|= extends-a slight the supply of compressed vair and theregion in the power cylinder to the rear of the'hammer Li'element is blanked before the blow is delivered,

but it will be understood that the stroke of the element is completed under the expan- 2.-sive..forces of the body of compressed air in passage l5 and in cylinder l I to the rear of the ham- =mer element.

"As the hammer element moves forward in blowdelivering direction, the body of air between the piston 35'gand the hammer element is: compressed to superatmospheric pressure,"*- and? under such pressure seeks escape through" a port: 22::and: a passage 24. A pressure relief valve P217 stands in 2.", communicati'oni with such portand passage 1 and such relief valve is adapted: to 'open at' a c'ritical pressure well below the pressure of the air 'that drives the -hammer element forwa'rd, but rsufiiciently higherthan atmospheric value to operate but' sufiicienflintervalbelow the plungeif'fi :and 3c the-sleeve-valve 2 l. More particularly;the sleevecooperatestvith' a spring ba'cked -"detent '-3 6' in yle'ldin'gly securing the plunger valve:- in its alternate i positions. The laiodv 'of "the 3 piunger 'ivalve includes a circuinierential' groove I -and a passag 4l;

one of the two-"lines'i of flow', alluded torabove, is-prc'a'vided by a relaitively dong-passage: 9 that establishes con1munication between 'v a port 89in the wall of valve-cylinder 5 and a port [0 in the valve 2! is arranged in an' annular or'cylindrical sli'deway 43 in'the b'ody of the gun; the sleeve- :valve is slotted, and a 'pin-'3'l;= secured in the gun body, extends into such slot and prevents sleeve- 35 valve rotation; the sle'eve-valve includes two portsthe portffl already-mentioned; and apart 2 3-; the sleeve walveis reciprocable' axially between the position shown, -in"which port "I 1': registers with the ports' lfi an'd l8; =and a position inwhirh -is -prov'ided -by a relatively shortpassage?!2 open- "ing at one 'end in-the'valve -cylinder and'atioppo- :sitemnd in the :power cylinder.

I) 'A -by-pass l 3 'of =relatively small diameterex- 'Wheri' -the port I T is in registry with ports ii 5 andulu communicatiorr is established between the p assage l 5 and" the power c'yli'ndergas shown", and ="vvhenport-I23- is register'ed 'with ports 25 and' zfi fellas fmmWhpasSag 9101116 D W y 4 pommunication is established between the power and opens into such cylinder at a point between the Episton 3 Sand theMammer element ll "When thevalve 6 isin tneiposition i11u'strated,- its gro'ov'e 1 establish'es communication between; were 3 I61 passage icand port 8 o ipassage 9; thethe'valve to:theleft' of the-groove blanks theiport 1'4 wand-Ethe passage 4 l in th body: of the valve lesta'blis'hes, with passage 32;Jcommunicati'on between th'eregion H it in the'power cyilinder on the cy-lindera'nd the outer atmosphere.

} 'I'he passage 24 opens into the forward end of the cylindrical 'slideway 53," as: indicated at '44, "and communicationis established between the 'dy 0f '60 "powercylinder l and the rear end of the slideway, by means of slots 38 formed in the rear edge of the sleeve-valve 2|. As the hammer-element approaches-theendof its powerstrokeand delivers a blow to'the -mead-" of'the ram, the

left -of the' -piston as. and. aquassage 'fl opening pressure of the air compressed between? the p15- 'to 'the outeratmosphere.

Assuming that allpartsfioi 'the gun arei in' the positionsiiillustrated'iwhen theitrigger isi' pressed, "itflwill 'be seen Ltha't thefic'ompressedair 'enterin'g passa'g e kilowsthrouglr ports 3iand' 8:into passage '6 9. flWhile 'thefioutl'et port llllofrpassage Blist as shown, 'closed byf the'ibodyiof the hammer element lhiair' 'enters" the power' cylinder; byrway of by- Epass= I3sandf forcesithei'hammer; element in rie'ftito-rightfdirecti'on; theibody of th' hammer elevfm'e'ntl is 'circumferentially lfeC8SSEd" bBtWeBn two shoulder328 rename; fandzmzsuch"leflatmnght movenientl'offthe :heimmer: elementithezshoulder maria-married itorthe i'rig'htiioff port in: with 'the 5 rinfluence of theair compressed between the hammer element and piston 35,-the :hammer element ie-moved in reverse direction, to the'right-hand limit of its' right-hand end oftherange of're- 'z'ciprocation. "This body "of compressedr'air be- -consequence that air' flows 'from:passage 9:into'70" tween 'the' hammer element and the piston'35 a passage l5, -the: passage :15 opening :into "the powenylind'er l'l through a port I2. Frompas- I liand'i l B- in-to the pow'er cylinder andidrives. the

ihammer elementtorward in its first: poweristroke,

:soper-ates toprevent retrograde movement *of the 1am in the intervals between the ram-impelling strokes of-'the hammer element.

filni' sucnreverse movement or the hammer ele- (by the body of theihammer ielement) closed,- and, since the port I1 is then out ofregistry with ports I 6 and I8, an air cushion is formed between the end wallof the power cylinder II and the hammer element. This air-cushion is of 'manifest utility in arresting. the left-to-right move-' ment of the hammer element suddenly but without violence. Additionally; the'pressure of; the air in such cushion, transmitted throughslots'or ports 38 to the right-handend of slideway: 43, efiects the 'return of the slide-valve 2| tov its original position-in which position it is here shown. Thus it is that the line. of airflow from passage 9 to the port [8 is re'-established,-and.air at supply pressure is again caused to;drive the hammer element through its blow-delivering stroke. J i

In such manner the hammer element'is automatically reciprocated, delivering a succession of blows to the head. of the ram [9. The hammer blows drive the ram step-by-step through its lubricant-delivering stroke, and it Willbe noted that the power cylinder is' vented on they left of the piston 35, through passages 32, 4|, 42, to the outer atmosphere, so that the ram need 'notand does not operate against ,a 'superatmospheric pressure. When the ram approaches the end of its working stroke, its head 30, coming to abutment upon the tip of the rod vorfinger 3|, carries the valve 6 in right-to-left direction into its a1- ternate position. As the valve 6 enters its said alternate position, the ports 3 and 8 areblanked, and communication is establishedbetween port 4 and passage 32; Thus, the passage 9 is closed to the supply of compressed air,and the hammer element comes torest, whileair at supply pressure flows from'passage 2, throughport 4 and passage 32; into -;the forward end 30f the power cylinder. Under the pressure of such air on piston 35, the ram moves incleft-ito-right'direction,

and returns-to the starting point ofits Working stroke. In such-return movement oi'the ram, the piston 35 engages and shifts'the -rod 3| in left-to-right direction, thereby restoring the valve 6 to its illustrated position. 'I'husyas the ram re-enters-initial position-and the cylinder is recharged with lubricant,'communication is re-established between passages 2 and; 9, with the consequence that the hammer element is again set inreciprocation', and the ram is again 1 driven througha lubricant deliveringstroke; It

will be perceived thatso long asthetrigger T is pressed inward, the operation described will continue. Alternately, when the trigger is released and the flow of compressed ,airto passage 2 interrupted, the operation :is' arrested.-- j

' As already mentioned, a valuable feature of the invention resides in structure that prolongs the interval in which the port- E-remains open to the flow of' lubricant from supply Container C to cylinder 23, and ashas ,beenalso} mentioned thisdesidra'tum is in -this' case obtained by'reof the power cylinder and air-supplying passage 2 ismade relatively small,:?-so thatithe flow of airinto the cylinder :isrestricted to suchvalue that the ram moves withithe desired low velocity into lubricant-admitting position. In this case, I advantageously provide a needle-valve 45 to regulate the effective area of such air passage. By adjustment of such needle-valve, the flow of the ram-operating air into the forward endof the cylinder may: be minutely regulated.

Whenqinservicethe store of lubricant, in container .C has been.exhausted,- the container is removed from barrel B and re-charged.

Many variations and modifications of the structure described are permissive within the terms and intent of the appended claims I 'claim as my invention: I 1 3 I I 1;-In a lubricant gun including a ram adapted to deliver from the gun lubricant under high pressure, a, pneumatic hammer adapted with repeatedblows to drive said ram through its lubricant-delivering stroke, and a passage for hammer-operating air; the improvements herein de scribed that comprise means 'for'returning said ram from the end to the starting point of its lubricant-delivering stroke, said means including a pneumatic cylinder, a piston carried by said ram independently of said hammer and reciprocable in said cylinder, and a valve movable into position to'by-pass air from such passage to said cylinder as the ram approaches the end'of its said lubricant-delivering stroke.

2. In a lubricant gun including aram adapted to deliver from the gun lubricantunder "high pressure, a pneumatic hammer adapted with repeated blows to drive said ram through its lubricant-delivering stroke, and'a passage for'hammer-operating air; the improvements herein'described that comprisemeans' for returning said ram from the end to the starting point of its lubricant-delivering stroke, said means including a pneumatic cylinder, a piston carried by said ram independently of said hammer and reciprocable in said cylinder, and a valve movable into position to by-pass air froms'uch passage to said cylinder as the ram approaches the end of its said lubricant-delivering stroke, said valve being adapted, upon movement into such position, to interrupt the flow of operating air to said hammer and to arrest the operation of such hammer while the ram'is in course of such return movement.

3. 'A lubricant gun including a lubricant-ejecting ram, a pneumatic hammer including a ham mer element reciprocable in a pneumatic cylinder and adapted to drive saidram through its lubricant-ejecting stroke, a passage for compressed air leading to said hammer, inlet and outlet ports for compressed air in said hammer, a pneumatic valve controlling the hammer-operating flow of air through said ports; and a valve arranged in said passage and operable to'control the flow of air to the first valve, said first valve comprising a ported valve member arranged in a pneumatic I valve chamber and movable, under the influence of pneumatic pressure in said gun, between alternate port-controlling positions.

4. A lubricant gun including a pneumatic hammer whose hammer element consists in a plunger in a pneumatic cylinder, a lubricant-ejecting ram extending inward into said cylinder, and a system of ports and passages and valves organized with said cylinder for controlling the supply and release of compressed air, to effect the movement of said hammer element'against the end of said ram and the travel of the ram in lubricant-ejecting direction; the end of said pneumatic cylinwits alternate positionsg -impelling "atmospheric pressureito said valve'for the valve between suchpositions'.

uerg into whi'ch 'said ram extends comprising ian airtrap in whichl-thi hammer elementpmovirig through a ram -driving strokepformsianIairLcushions said 1 cushionbeing iadaptedgt fafterimpact of the Y h'ammer i elementfi'with the ram;- 1to return lsdch' ha'mmerelement to the starting :1point 'of such str'oke. Y 1 I 5. Alubricantgun in'cluding atpneumatichammen whose' hammer' elementcon'sistsfiin wnmger in af pn'eum'atic ylinder g a lub ricant ejecting ram extending-inward=into said cylizi'der; and a system of. ports -'andpassages and' valves organized with said cyliiider 'iori controlling thei supplyand release or compressed airS-to fiect the movement of said hammer elem'ent ain'stI the end "of said ram and! the travro'f maram in lul oriba'nt ej ecting dirctionfi the 'efid of said pneumati'c" cylinder into which saidi ram extends comprising an: air trapE f-in Which fthe fshammer (element: oving through aeram-drivmga strokepformsxan iairl'cu'sh: ion, onezof rsaidwvalves acomprising a;valv mem'-' hem movable'mbetweena ialternata poSitions :i'n: a pneumaticwaiveichamber, OIle'iOf: the passa'ges of sai'd.:system' leading from .the': airscushionzend 7 of said pneumatic cylinder to said'zvalveachamber, wherebyi-thepressure of 'the bodymf'am compressed ;by 'thewhammerelementin such:- cylinder is transmitted to-said valve chamber; tow'efiect the *--movement of-"said valve member between alternate positions. -e V V I g I 6. In apparatus'- of theaclass described-includingr alub-ricant cylinder- -having an' inlet, a ram for ejecting lubricant from. said cylinder,- a--pneumatia cylinder axiallyaligned With-said ram, a plunger reciprocablei in said 4 pneumatic .cylinder .to-. drive said ramthrough i its -luhricant-ejecting stroke; i an inlet-passage for delivering compressed rair -intoe'saidpneumatic oylinder to the-rear of ysaid plungeruto impell theplunger-against said ram,-.an pneumatic mylinderto-t hea rear of. said -plunger, (and 'asvalve-movable between a -position in which isaidlinletpassage' communicates withsaid gcylintdereland-ssaid i outlet epassageris blanked,-' and a -positionrin =which-.=said outlet-:passage-rcommuni- .c'ates with said, cylinder-u and-r'said- -inlet' passage wis:blanslkelzl and a passage leading'fmm saidpneulmatic cylinder: (:tOthBvfOI'Gf of said .plunger) to saidvalve,- whereby :air compressediby the plunger moving in said cylinder into ram-driving position -is suppliedwo -said valve foreffecting movement of 'the valve from one-to-the other of 7-. In apparatus of; the class described-"includingv a luoricant :cy linder having-an 1inlet-airam forej ecting lubricant fromsaid icylinder; apneumatichammer arranged to -l-driveo-said o ram t-hr-oughe.itsJubricant-ejecting stroked-said haml'mer l comprising a pneumatic. cylinder; a :ram-

inlet passage fore delivering compressed *airinto said pneumatic cylinder-to .the-l-i-rear obsaid Lplunger: for iimpelling the plunger into ram -driving' position, an--outlet passage'lfor releasing air from said pneumatic fcylinder' to the 'reanvof said plunger; apneuma-tically operated airvalve movable -1aetween alternate passage-controllingposi- --tions,' and passages for supplying air at supershiftin 8.-.-Apparatusof the class; described ='-inc1uding alubricantcylinder and a iram for 'forcinglubricant from suchrzcylinder," a' pneumatici hammer -for driving ingistroke', aipisto'n'. movablein: aipneumaticlcylinjectsaidi'ramithrou'gh its lubric ant-t ontlet-.;: assage for releasi-ng air from said i plungerimsaidpneumaticrcylinder, an

der-t-for returning 'saidi-ramrfr'omxthe endto the start of;s1'1clustr0ke, passages leading from a supply-'ofzcompressed air. to: saidpneumatic hammer and said pneumatic cylinder, a valve controlled by saidsram :and movable between a position in whiclr the-"passagetossaidzhammer islblank'ed and the passagertoiuthe "pistone-including :cylinder: is openlandaapo'sitioir in'whichithe passagezto the hammer." is open iand Lthat: to [the rpiston=including cylinden-is blanked.

9. riIn iapparatus :of the: classidescribed including a clubricantir'cylinder 'and. a :ram: for iforcing lubricantlfromisuchx cylinder; a pneumaticzhammeriifor l driving: said 'ram through. its lubricantejectingistroke, a1pistonmovab1e'.ina pneumatic cylinder 'forretuming; said Tram" from the end to the start of such stroke, a. passage for compressed air ileadingwzto said: pneumatic hammer," 'an exhaustpassage mpening fr'orm said pneumatic hamm'eritorztheiouter atmosphere; a valve movable between a' position-iinwhich said compressed air passageiisi 'openzzand said exhaust passage is closed and a positi'on' in which'saidexhaust passage'isopen and saidicompress'ed air 'passa'ge is cl'osedfiand a passage for compressed airleading to said pneumatic piston including 'cylinderyand awalvetcontrolling'the last-mentioned passage.

- 10:: An "app'a'ratus' of the. Classdescrib'ed cOmprising a cylinder rthat provides a container-for a charge a. 1ubri'cant;:an outlet opn'mg "from said rcylin'der'; a ram; ai -pneumatic: hammer; a trigger-2 controlling" the delivery of compressed air to saidshammer; said pneumatic' hammer including: athammerl'eleme'nt adapted to reciprocate continuously; "when said trigger :is' in airdelivering' position, to drive said" ram through a 'ilubricant delivering stfoke'f in said cylinder, 'means'iincluding a'pn'eumatic -valve' for automatically arresting' operation of said "hammer element when, 'with" the 'trigger' still' in .air-de- 'livering position;' said 'ram" reaches the end "of its lubricant-delivering 1 stroke, and means for automatically returning "said ram to the begin- "ning 'ofits'range inf-reciprocation while'the op- 'erat1on"of said hammer element is'so'arrested. 11. A grease'gunf including alubricant'cylinder with an outlet; a ram movable in such cyliiider between lubricant receiving position and lubricant-delivering position, and a' pneumatic hamm'en adapted with repeated blows 'to" drive s'aidram through its lubricant delivering" stroke 'in -safid. cylinder; "a passage' for hammer-motivating compressed 'air" leading to said pneumatic hammer, and 'means for automatically arresting the operationof"the"'-hammer wherr the ram reaches theend "of said lubricantd'elivering st-roke','said means including a valve in said air passage and a'portion'carried by said ram and arranged f to engage "the valve and shift it into "air-passag-blanking position when the ram i reaches s'ai'd'end'of its" stroke.

12;- A grease gun including alubrica'ntmylinder with-an outlet, a'ram'movable in suchzo'ylin- 1 der between" lubricant-receiving position and P lubricant-delivering position, and" a pneumatic stroke; said'tmeans' including a valve insaid 'air ipassa'ge a'ndi a 'portion carried by said ram and garrangeditol.iengagefthe .valve and: shift it. into air-passage-blanking position when the ram reaches said end of its stroke, and pneumatic means for returning said ram from the end to the beginning of its stroke while the reciprocation of the hammer is so arrested.

13. A grease gun including a lubricant cylinder with an outlet, a ram movable in such cylinder between lubricant-receiving position and lubricant-delivering position, and a pneumatic hammer adapted with repeated blows to drive said ram through its lubricant-delivering stroke in said cylinder, a passage for hammer-motivating compressed air leading to said pneumatic hammer, and means for automatically arresting the operation of the hammer when the ram reaches the end of said lubricant-delivering stroke, said means including a valve in said air passage and a portion carried by said ram and arranged to engage the valve and shift it into air-passage-blanking position when the ram reaches said end of its stroke, and pneumatic means for returning said ram from the end to the beginning of its stroke while the reciprocation of the hammer is so arrested, said last means including a device for efiecting retardation of ram movement in said returnstroke.

14. A grease gun including a lubricant cylinder with an outlet, a ram movable in such cylinder between lubricant-receiving position and lubricant-delivering position, and a pneumatic hammer adapted with repeated blows to drive said ram through its lubricant-delivering stroke in said cylinder, a passage for hammer-motivating compressed air leading to said pneumatic hammer, and means for automatically arresting the operation of the hammer when the ram reaches the end of said lubricant-delivering stroke, said means including a valve in said air passage and a portion carried by said ram and arranged to engage the valve and shift it into air-passageblanking position when the ram reaches said end of its stroke, said ram carrying a second valveengaging portion adapted, as the ram approaches the end of its return movement, to engage and shift said valve into its original position in which said air passage is open, with the efiect that the arrested hammer is again set in operation.

WILLIAM L. OSTENDORF. 

